Vitamin D status and circulating biomarkers of endothelial dysfunction and inflammation in non-diabetic obese individuals: a pilot study

INTRODUCTION: Obesity and inadequate vitamin D status are associated with endothelial dysfunction and cardiovascular disease. We evaluated the associations between vitamin D status (i.e. serum levels of 25-hydroxyvitamin D (25(OH)D)), biomarkers of endothelial dysfunction (i.e. serum concentrations of soluble intercellular adhesion molecule 1 (sICAM-1) and soluble E-selectin (sE-selectin)), inflammatory markers (i.e. high-sensitivity C-reactive protein (hsCRP) and fibrinogen) and cardiometabolic risk factors. MATERIAL AND METHODS: Fifty obese (body mass index (BMI) ≥ 30 kg/m(2)) non-diabetic adults (mean age: 36.2 ±5.4 years) without pre-existing cardiovascular abnormalities and 25 clinically healthy, normal weight and age-matched individuals were included. Anthropometric parameters, markers of glucose and lipid metabolism, and serum levels of inflammatory and endothelial dysfunction biomarkers were assessed in all subjects. RESULTS: The mean serum 25(OH)D level was significantly lower in the obese group than in controls (33.5 ±15.2 vs. 60.1 ±23.1 nmol/l; p < 0.001). In the obese group, sE-selectin (36.4 (32.1–47.2) vs. 32.4 (24.6–35.5) ng/ml, p < 0.05) and hsCRP (6.0 ±3.4 vs. 3.5 ±1.0 mg/l, p < 0.05) were significantly higher in individuals with lower than median vitamin D levels (i.e. 31 nmol/l) compared with those with higher vitamin D levels. In multivariable linear regression analysis, hsCRP (β = –0.43; p < 0.001) and sE-selectin (β = –0.30; p = 0.03) were independently and significantly associated with serum 25(OH)D levels in the obese group. CONCLUSIONS: Vitamin D levels may be related to increased levels of biomarkers of endothelial dysfunction and inflammation in obese non-diabetic individuals.